Recently, OLED (Organic Light Emitting Diode) as new flat panel display technology has received more attentions. OLED may possibly become a next-generation display technology replacing liquid crystal displays because it has active emission, high brightness, high resolution, wide viewing angle, fast response, low energy consumption and flexibility.
The commonly used RGB light emitting units in the most of current OLED device structures share a common hole injection layer (HIL). Using HIL as a common layer can reduce a reticle and related processes and thus the process flow is simplified. However, there is a problem with this solution that, when a turn-on voltage is applied to a unit device of one color, directional transmission of carriers may occur due to the good carrier-transporting performance of the HIL and a large difference (i.e., voltage difference) in the turn-on voltages of devices of different colors, as a result, unit devices of other colors are also turned on. This problem is more serious in low gray scales.
Thus, it is desirable to provide a method of manufacturing an OLED device and an OLED device capable of alleviating or solving one or more of the above problems.
It should be noted that the information disclosed in BACKGROUND is merely for enhancing the understanding of the background of the present disclosure and therefore may contain some information that does not pertain to the prior art that has already known by those with ordinary skills in the art.